IN（）不在mysql存储过程中工作

DELIMITER $$

USE `employee`$$

DROP PROCEDURE IF EXISTS `selectemployeebyids`$$

CREATE DEFINER=`root`@`localhost` PROCEDURE `selectemployeebyids`(IN empid VARCHAR(100))
BEGIN
    SELECT empname,salary,department from emp where empid IN (empid) ORDER BY empid;
    END$$

DELIMITER ;
DELIMITER $$

USE `employee`$$

DROP PROCEDURE